Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. These smaller electronic components can introduce challenges into manufacturing process flows for semiconductor devices.
Transistors are elements that are fundamental building blocks of electronic systems and integrated circuits (ICs). Transistors are commonly used in semiconductor devices to amplify, switch electronic power, and perform other operations. Some recent designs of transistors include high electron mobility transistors (HEMTs) which have low voltage operation, increased speed, and decreased power dissipation than traditional complementary metal oxide semiconductor (CMOS) devices, and vertical transistors, which have multiple gates.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.